Engines (except Modified class)
1. Original HP limited to class being entered.
2. Stock stroke, however bore may be a maximum of .050 oversize.
3. Must be a lawnmower or lawn tractor engine. (factory design)
4. Any type of oil pump allowed.
5. No pressed steel cranking pulleys allowed.
6. Must have an engine kill switch at rear of tractor within 6" of center.
7. Exhaust must be directed upwards away from track.
8. Must be naturally aspirated and must use a factory type carburetor.
9. Must use original engine manufacturers carburetor, recast allowed.
10. Overhead valve engines may be run in any class.
11. Overhead valve engines will not be considered legal if the same engine, relative to design and displacement, is labeled by the manufacturer at a higher HP than the class being entered.
12. In Kohler engines where the cylinder casting is common to several HP's, it may be bored or sleeved to meet bore size for class being entered.
So bassically we can bore it, port it, use recast carbs from midwest or lakota ect... , put the big valves in it, use the billet cyl. heads, billet rods, the steel flywheels.
